PHP and XML: How to deal with ":" in node name? [duplicate]

This question already has an answer here:

• How to get the property of an object which has a dash (-) in between name 1 answer

I have XML file:

<article>
<itam:name>Title</itam:name>
<itam:link>url_to_itam</itam:link>
</article>

And a PHP script that generate file from that xml feed:

<?php
    $file = "file.php";
    $html = "";
    $url = "http://ift.tt/13ImNq3";
    $xml = simplexml_load_file($url);
        for($i = 0; $i < 10; $i++){
        $link = $xml->article[$i]->itam:link;
        $title = $xml->article[$i]->itam:name;
    $html .= "<a href=\"$link\">$title</a>";
}
file_put_contents($file, $html);
?>

This script is working for other feeds but not for that one, I'm getting error:

PHP Parse error:  syntax error, unexpected ':'

What I can do with ":" in node name?